In terms of what makes a website convert, the only thing you can truly trust is the behaviour of a significant number of visitors.
Don't trust articles that tell you what converts best (though they may have good ideas and they could well be right). You never know for sure until you run it by lots of customers.
We highly recommend usability groups to find out areas of your site with which you can experiment, just don't trust what you're told until you've thoroughly tested it.
Testing using Google Optimiser is a simple way to run A/B and multivariate testing experiments. For more information on this, read up on Conversion Rate Optimisation.
